I have the Standard Touring Bags from Willie and Max - the deepest, flat-bottomed bags they offered. Straps and buckles with the plastic quick disconnect hidden under the straps (kind of renders the so-called lock useless if one could undo the buckle and open 'er up?), but I have thought several times over the last year that the simple hook-and-loop (velcro) closures would be more than adequate, and certainly more convenient at times....
UNTIL,
I want to over-stuff the bags and have to use the strap to crank down the flap because I can't fasten the plastic clips because the bags are too full
or UNTIL
the hook and loop wears out or weakens and fails to hold the flap down at speed
Security really is not an issue - I never worry about anybody trying to mess with my bike or get into my stuff while it is parked somewhere and I am away - and I'm in HOUSTON. I just don't think too many people are going to mess with a man's bike, but maybe a a large rally somewhere it might be a different story.
The bags I REALLY liked, but was a little hesitant to try the EasyBrackets with, are the:
Oxford Sport Saddlebags